The streaming or downloading of digital files has become a dominant mechanism for delivering content to a wide range of devices. Increasing consumer demand for higher and higher quality content poses significant technical challenges for existing infrastructure. Whether the content is video-on-demand (VOD) content or broadcast content (e.g., scheduled content or content being generated and delivered in real time), adaptive bit rate heuristics attempt to balance a number of competing priorities to deliver the highest quality user experience within available bandwidth.
One of the competing priorities affecting the user experience is reducing the likelihood of rebuffering events in which the playback of content freezes or prematurely terminates because the client has an insufficient amount of the content in its download buffer. Manipulating the size of the download buffer (e.g., how many seconds of content must be in the buffer to sustain playback) can decrease the likelihood of rebuffering events but may have an undesirable consequence such as, for example, increasing the time to first frame, i.e., the amount of time that passes before the first frame of the content appears on the display of the client.
The adoption of High Efficiency Video Coding (HEVC), also known as H.265, as a video compression standard promises to enable a significant reduction in storage and bandwidth requirements for a given quality of video content. However, given the expected continued growth in consumer demand and the introduction of higher resolution content, heuristics that attempt to strike an appropriate balance among the various competing priorities to deliver a high quality experience must continue to improve.